Electrical contact-making device and assembling the same



Aug. 27, 1929. R. B. BENJAMIN ELECTRICAL CONTACT MAKING DEVICE ANDASSEMBLING THE SAIE Filed Deo. 22, 1927 Patented Aug. 27, 193239.

STATES PATENT OFFICE.

REUBEN B. BENJAMIN', OF CHICAGO, ILLINOIS, ASSIGNOR TO BENJAMIN ELECTRICMANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLI-NCIS.

ELECTRICAL CONTACT-MAKING DEVICE AND ASSEMBLING THE SAME.

Application filed December 22, 1927.

My invention relates to an improved form of contact-making device ofespecial utility in circuits comprising electrical signalling apparatusthat is to be operated for short intervals only, as for example, asignal bell, motor-car horn, siren or the like.

One of the objects of my invention is to provide a contact-making devicecomprising a push-button of improved construction that readily lendsitself to rapid and simple assembly.

A further obj ect of my invention is to provide a push-button, of thetype generally in use on motor-cars for operating the warning f signal,in which the movable part of the button may be instantly attached anddetached from the balance of the contact-making device without the useof any tools whatsoever.

A further object of my invention is to provide a push-button of the typewhich may be operated either by a straight downward pressure on thebutton or a tilting movement thereof in which the button part may bereadily connected and disconnected with respect to the base part.

Other obj ects will appear in connectie with the description anddrawings that form a part of the present specification. In the saiddrawings:

Figure 1 is a top plan view of my improved push-button contact-makingdevice as it appears when applied to the center of a steeringwheel of amotor-car;

Fig. 2 is a sectional elevation of the device showing its interiorconstruction;

Fig. 3 is a bottom plan view of the pushbutton proper showing the meansemployed for retaining the same in assembly with the main housing of thecontact-making elements Fig. 1L is a side elevational view of thepushbutton shown in bottom plan view of Fig. 3;

Fig. 5 is a detailed elevational view of the manner in which the singlewire leading to the device is provided with a contacting tip or end; and

Fig. 6 is a detail of a metallic disc that serves as one of theelectrical contacts in the device.

Referring for the moment to Fig. 2, it will be seen that my improvedcontact-making device comprises a shell of molded insulating material 11having an open interior space 12. The interior walls of this space aresubstantially vertical, but the space is somewhat con- Serial No.241,851.

stricted at the top thereof by the crimped or projecting edges 13. Thegeneral shape of this shell is not material, and it may consist of amolded phenol resin material, or of porcelain or other substance thatdoes not conduct electric current. The edge 13 forms a fulcrum againstwhich the edge of the button operates when pushed otherwise thanccntrally.

The shell 11 is attached to a supporting surface, such as a wall, table,or, as shown in Fig. 2, to the metallic spider 14 of a steering-wheel ofa motor-car. This metallic spider 14 is attached to the metallicsteering-post 15 of the motor-car. The latter is, by reason of the factthat in most modern motor-cars that are provided with a storage batterythe negative side of said battery is connected with the metallic frameof the car, in metallic conducting relationship with the negative poleof the said storage battery.

The shell 11 is secured to the spider 14 by means of the screws 16 orAtheir equivalent.

Between the insulating' shell 11 and the metallic spider 14- there isinserted a metallic disc 20. This is in the form of a flat disc providedat its center with an opening having an upwardly extending flange 21,turned over at its upper edge 22 as seen in Fig. 6. This disc isprovided with a number of holes 23 through which the screws 16 pass;although it may merely be notched to accommodate these screws. Theobject attained is to place this disc 20 into direct metallic contactwith the spider 16, and hence with the negative side of the battery onthe motor-car. The upper edge 22 of the disc 20, therefore, serves asthe negative side of the contact-making device.

The upper, movable part of my improved contact-making device comprises amolded insulating push-button 30. rFhis button has inserted and moldedinto it, during fabrication, a hollow metallic bushing 31. An annularflat metallic member 32, whose opening closely corresponds with anoutside diameter of the bushing 31, is slipped over the end of thelatter, whereupon the bushing 31 is rolled or crimped over the flatmember 32, thus keeping the same tightly in place, while also securinggood metallic conducting contact with the same.

A resilient metallic, preferably bronze or brass, spring 33 is placedinto the interior of the bushing 31, being retained therein by itstapering form and especially by the last turn 33L of the spring which ismade slightly larger than the other turns, s-o that it will, when pushedinto the bushing 31, expand into the enlarged end of the same and beretained thereby. The spring 33 is suiiiciently long so that it willextend, when but slightly compressed, to about the level of the lowersurface of the metallic disc 20, but as the said disc is hollow, will,of course, not contact with the same.

Placed on the metallic spider 16, or in a recess in the center of thesame, there is a disc of a non-conducting material, preferablyvulcanized liber, hard rubber, laminated phenol-resin or the like.rl"his disc has a central perforation through which extends the end of awire cable 50. This Wire cable is connected with the positive side ofthe storage battery already referred to.

The cable 50, provided with a protective covering 51 to prevent shortcircuits, is attached to a special form of terminal contact, as shown onan enlarged scale in Fig. 5. This terminal has a disc-like portion 52and an upwardly extending` tubular portion 53. ln assembling the cableto the terminal the end of the cable is pushed through the tubularporti-on 53 of the staple, whereupon the latter is twice crimped as atthe points 53 and 54, thus firmly attaching the staple to the wire, andplacing the former in good metallic contact with the wire. The planes ofthe crimpings preferably cross each other at right angles.

TWhen assembled in the completed contactmalring device, as shown in Fig.2, the smaller end of the spring 33 will abut against the disc likeportion 52 of the staple, the tubular portion of the staple extendingupwardly within the convolutions of the spring 33. `When thus assembled,therefore, it will be seen that the positive side of the battery will beconnected with the spring 33 and the disc 32.

lf now the push-button 30 is depressed, the disc 32 will contact withthe disc 20, completing the electrical circuit and operating the signaldevice that is associated with it. By reason of the disc-like shape ofthe contacting members 2O and 32, this contact will be established eventhough the button 30 be pushed from one side, so that positive andcertain operation of the contact-making device is secured. In the lattercase the button operates like a telegraph key, forming the equivalent ofa lever of the second class with the fulcrum at the projection 13. Theactual pointat which the fulcrum forms will be diametrically oppositethe point where the button is pushed. The button is prevented from beingpushed out 4of the shell 11 by being provided with a plurality ofoutwardly extending tangentially disposed. resilient members 60, whichare part of a. sleeve 61, which surrounds the narrow part of the button30, as shown in Figs. 2, 3, and 4l. This sleeve may form either a partof the disc 32 or may be separated therefrom and placed between the disc32 and the body of the button 30.

The spring members 60, in their normal positions, extend under thecrimped edge 13 of the shell 11 and are held against this edge by reasonof the resilience of the spring 33, which tends to push the button 30out of the shell 11. As will be noticed in Figs. 3 and l, the springmembers extend tangentially from the sleeve 61, all pointing in the samedirection. Assume now for the moment, that the button 30 with its spring33 and sleeve 61 and projectingspring members 60, as shown in Fig. a, beplaced in the opening 12 of the shell 11 and then rotated in a clockwisedirection (counterclockwise as shown in the bottom view of Fig. 3), theprojecting spring i members 60 will tend to be con'ipressed and will liefiat against the sleeve 61 so that the button 30, and the assembledparts thereon, can be pushed downwardly past the crimped edge 13 intothe space 12. As soon as this takes place, the spring members 60 willagain assume their original tangential positions and will thereforeprevent the button 30 from being pushed out of the space 12 by thespring 33.

However, when it is desired to remove the button for purposes of repairor inspection, it suliiccs to pull upon the same while rotating it in aclockwise direction, when the action just described will repeat itself,the spring members 60 will be again compressed, and the removal of thebutton thereby made possible. lt will thus be noted that the assemblyand disassembly of the button 30 and the sleeve 61 with theappurtenances thereto attached can be accomplished without the use ofany tools whatsoever, in an extremely simple and eflicient manner.

Preferably, the outside dimension of the cylindrical portion of thebutton 30 is made just slightly smaller than the internal diameter ofthe crimped fulcrum flange 13, so that there will be a fairly close fitwithout however binding upon the button. There should be enoughclearance, however, to insure that the button will not stick in Contact,but will return to the position shown in Fig. 2 as soon as the pressureupon its upper surface is removed.

Vllhere the wire cable 50 passes through the center of the steeringcolumn 15, it is provided with a covering of loom 51 so as to preventshort circuits and the undesirable operation of the signal devicecontrolled by the contactmaking device.

While for the sake of simplicity it has been stated that the wire 50 andthe spring 33 and the disc 32 are in contact with the positive side ofthe battery, it is to be understood that the signalling device which isto be operated will be cut into this part of the circuit as the disc 2Ocorresponds to the ground side of the circuit and, therefore, theoperating device must be placed somewhere along the line of the cable50.

Obvious modiiications in the shape and method oi" assembly of myimproved contactmaking device and such as would constitute equivalentstherefor are to be considered within the scope and intent of my presentinvention, for which I claim l. An electricalv contact-making devicewhich comprises a push-button made of insulating material andcomprisinch a top portion and a shank portion and resilient wing memberson the shank of said button, the latter being 'oldable against saidshank.

2. An electrical contact-making device which comprises a push-buttonmade of insulating material, yieldable means for supporting saidpush-button, and resilient wing members on the shank of said button, thelatter being oldable against said shank.

3. An electrical contact-making device which comprises a push-button ofinsulating material having a top portion and a shank portion, resilienttangentially extending wing members on the shank of said button, and ahousing of insulating material; said wing members being foldable againstsaid shank and insertable together with said shank into said housing.

4. An electrical contact-making device which comprises a push-button ofinsulating material having a top portion and a shank portion, resilienttangentially extending Wing members on the shank of said button, ahousing of insulating material; said wing members being oldable againstsaid shank and 6. A push-button switch construction com-V prising astationary contact, an insulating housing therefor having an opening andhaving an inwardly extending annular flange surrounding said opening, apush-button comprising a top portion and a shank, a second contactcarried by said push-button tor cooperation with said first contact, anda plurality of tangentially extending leaf springs spaced about saidshank portion and secured thereto, the free ends oia said leaf springsbeing movable toward and from said shank and being compressiblesufficiently to permit the shank carrying the springs to be insertedthrough said opening, and being eX- pansible sufficiently to engageunderneath said flange when inserted whereby said button may beassembled with respect to said casing by placing the shank inregistration with the opening and pushing the shank and the springcarried thereby into the casing while 'rotating the button.

In witness whereof, I have hereunto subscribed my name.

REUBEN B. BENJAMIN.

